Crystalline polymers of propylene oxide



United States Patent 3,468,817 CRYSTALLINE POLYMERS OF PROPYLENE OXIDE Henry L. Hsieh, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware No Drawing. Filed June 7, 1965, Ser. No. 462,102 Int. Cl. C08g 23/14, 23/06 US. Cl. 260-2 8 Claims ABSTRACT OF THE DISCLOSURE 1,2-epoxy propane is polymerized in the presence of a catalyst system formed by mixing an organoaluminum compound and a vanadium-containing compound. The polymer product has increased crystallinity when the polymerization is carried out in the presence of dicyclopentadiene. These polymers can be used as sizes and vehicles in the textile and paint industries, in the preparation of films, and in the fabrication of various shaped articles.

This invention relates to propylene oxide polymerization. In one aspect, this invention relates to processes of polymerizing propylene oxide. In another aspect, this invention relates to high crystalline propylene oxide polymers.

A conventional process of polymerizing propylene oxide involves the use of a catalyst system comprising an organoaluminum compound and vanadium acetylacetonate. Although this type of catalyst is reasonably good for effecting polymerization, the resulting polymer has only a fair degree of crystallinity. In the fabrication of certain articles from polymers of propylene oxide, it is desirable to use a high crystalline polymer. In these instances, the propylene oxide polymer produced by the processes of the prior art is unsatisfactory because of its low degree of crystallinity.

According to this invention, this disadvantage of the prior art processes is overcome by providing a process which will result in the production of high crystalline propylene oxide polymers. This result is achieved by employing dicyclopentadiene as an adjuvant during the polymerization. Although it is not known for certain just how the dicyclopentadiene functions to increase the crystallinity of the polymer, it has been discovered that the crystallinity is increased by as much as 100 percent and often by as much as from 200 to 400 percent when the adjuvant of this invention is employed.

Accordingly, it is an object of this invention to increase the crystallinity of propylene oxide polymers.

Another object of this invention is to provide a process of producing high crystalline propylene oxide polymers.

A further object of this invention is to provide an adjuvant which can be used for increasing the crystallinity of propylene oxide polymers. h

Still another object of this invention is to provide an improved process of polymerizing propylene oxide.

These and other objects of the invention will become apparent to one skilled in the art after studying the following detailed description and the appended claims.

In the practice of this invention, the crystallinity of the propylene oxide polymer is increased by employing the dicyclopentadiene adjuvant in conjunction with a polymerization catalyst comprising an organoaluminum compound and a vanadium-containing compound. The dicyclopentadiene is present during polymerization of the propylene oxide such that the polymer produced has a high degree of crystallinity.

The organoaluminum compound of the catalyst system can be represented by the formula "ice wherein R is a hydrocarbon radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 20 carbon atoms, inclusive; X is a member of the class consisting of hydrogen, fluorine, chlorine, bromine, and iodine; n is an integer of from 1 to 3, inclusive; m is an integer of from 0 to 2, inclusive; and the sum of the integers n and m equals 3. organoaluminum compounds within the above formula include organoaluminum monohalides, organoaluminum monohydrides, organoaluminum dihalides, organoaluminum dihydrides, and organoaluminum sesquihalides. The organoaluminum sesquihalides as herein defined are intended to mean a mixture of organoaluminum monohalides and organoaluminum dihalides of the formulas R AlX and RAlX respectively, wherein R is the same as hereinbefore defined with respect to the general formula and X is a halogen. The organoaluminum sesquihalides can then be Written as R AI X or as R AlX Exemplary organoaluminum compound within the above formula include trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-decylaluminum, tri-n-eicosylaluminum, tricyclohexylaluminum, triphenylaluminum, methyldiphenylaluminum, ethyldi(3,5-di n heptylphenyl)aluminum, tribenzylaluminum, tri-l-naphthylaluminum, di-n-octylphenylaluminum, tri 4 tolylaluminum, dimethylchloroaluminum, methylchloroaluminum, n-heptyldifluoroaluminum, 3-ethylcyclopentyldiiodoaluminum, methylisobutylchloroaluminum, diphenylbromoaluminum, diben zylchloroaluminum, di n octylchloroaluminum, n-octylphenylchloroaluminum, di-n-eicosyliodoaluminum, n-butyldihydroaluminum, methyldihydroaluminum, diisopropylhydroaluminum, ethylmethylhydroaluminum, diphenylhydroaluminum, benzyl-n-dodecylhydroaluminum, dicyclohexylhydroalurninum, 2,6 di-n-butyl-4-n-hexylphenyldihydroaluminum, and n-amylethylhydroaluminum.

The vanadium-containing compound of the catalyst is selected from the group consisting of vanadium halides, vanadyl halides, vanadium salts of a beta-diketone, and vanadyl salts of a beta-diketone. Vanadium halides and vanadyl halides (vanadium oxyhalides) which can be used include vanadium tribromide, vanadium trichloride, vanadium tertachloride, vanadium trifluoride, vanadium tetrafluoride, vanadium triiodide, vanadium oxydibromide, vanadium oxytribromide, vanadium oxydichloride, vanadium oxytrichloride, vanadium oxydifluoride, vanadium oxytrifluoride, vanadium oxydiiodide, and vanadium oxytriiodide. The vanadium and vanadyl salts of a betadikctone can be represented by the formula wherein each R can be the same or different and is a radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 10 carbon atoms, inclusive; x is an integer of from 0 to 1; y is an integer of from 1 to 4, inclusive; and the sum of the integers 2x and y equals the valence of the vanadium V. The general formula for metal salts of beta-diketones is expressed structurally in Moeller, Inorganic Chemistry, page 241, Wiley and Sons, 1952.

Specific beta-diketones which can be combined with the Vanadium or vanadyl to form the corresponding vanadium or vanadyl salt include 2,4-pentanedione (acetylacetone); 3,5-heptanedione; 11,13-tricosanedione; 1,3 dicyclohexyl 1,3 propanedione; 1,5-dicyclopentyl- 2,4-pentanedione; 1,3 diphenyl 1,3 propanedione; 1,5 diphenyl 2,4 pentanedione; 2, 8-dimethyl-4,6- nonanedione; 1,3-di(4-n-butylphenyl)-1,3-propanedione; 1,11-diphenyl-5,7-hendecanedione; 1 phenyl-1,3-butane- 3 dione; 2,4-decanedione; and 1-(3,5-dimethylcyclohexyl)- 2,4-pentanedione.

The propylene oxide polymerization reaction can be conducted either as a batch process or as a continuous process with the catalyst system being added as a single initial charge or in predetermined increments during polymerization. Similarly, the dicyclopentadiene adjuvant can be added in a single increment at the beginning of the reaction or it can be added in predetermined increments during polymerization. The 1,2-epoxypropane monomer can be introduced into a suitable reaction vessel containing the catalyst and adjuvant as a single charge or the monomers can be added gradually during polymerization. In order to expedite and improve the efficiency of the reaction, it is generally preferred that it be carried out in the presence of an inert diluent. Suitable diluents which can be used for this purpose include paraflinic, cycloparafiinic, and aromatic hydrocarbons containing from about '4 to about 10 carbon atoms per molecule. Exemplary diluents which can be used separately or in admixture with each other are butane, pentane, hexane, decane, cyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, and the like. It is also within the spirit and scope of this invention to employ halogenated hydrocarbons such as chlorobenzene and the like as diluents. Since the actual diluent forms no part of the invention, it is possible to employ other diluents than those hereinbefore identified without departing from the invention. Mixtures of two or more of the diluents can be used if desired.

The mole ratio of the organoaluminum compound to the vanadium-containing compound in the catalyst system is within the range of from about 2:1 to 100:1 and preferably in the range of from about 5:1 to about 30:1.

Although the amount of catalyst used for effecting the polymerization of the propylene oxide is largely a matter of choice, the catalyst level is preferably and for convenience determined on the basis of the organoalurninum compound present in the catalyst system. As a general rule, the amount of catalyst is maintained within the range of from about 1 to about 100 gram millimoles of organoaluminum per 100 grams of monomer being polymerized and preferably in the range of from about 5 to about 40 gram millimoles of organoaluminum per 100 grams of monomer.

The amount of dicyclopentadiene adjuvant employed is generally in the range of from about 1 to about 50 parts by weight per 100 parts by weight of propylene oxide monomer. Obviously, amounts outside of this range can be used if desired. As a general rule, the adjuvant is present in an amount of from about 3 to about 30 parts by weight per 100 parts by weight of monomer.

The temperature and pressure at which polymerization is effected can vary over a rather wide range. Generally, polymerization is effected at a temperature within the range of from about 40 to about 250 F. and preferably within the range of from about 85 to about 200 F. Polymerization is usually conducted at a pressure which will maintain the materials in a liquid state. It is obvious that the reaction can be conducted at superatmospheric pressures of several thousand pounds if desired.

The duration of the polymerization reaction will depend primarily upon temperature, pressure, and the activity of the particular catalyst being used. Usually, the process will be conducted from a period of from about a few minutes or less to about 100 hours or more.

The dicyclopentadiene adjuvent of this invention, the catalyst level, and the ratio of catalyst components allow the crystallinity and the molecular weight of propylene oxide polymers to be controlled such that the properties of the final product can be varied and controlled. High molecular weight, highly crystalline products are easily obtained. The polymers having a high degree of crystallinity are relatively hard at room temperature, but they 4 achieve a rubbery state when heated slightly above room temperature. Moreover, the propylene oxide polymers prepared using the adjuvant of this invention possess a high green tensile strength. The polymers are extremely resistant to the effects of heat and ozone.

The polymers produced by the novel process of this invention have a variety of different uses depending upon the particular properties of the polymer. They can be used as sizes and vehicles in the textile and paint industries. The propylene oxide polymers can also be used in the preparation of films by conventional techniques such as milling, oalendering, solvent casting, and the like. The polymers can also be used in the fabrication of various shaped articles such as those used in the automobile industry.

The following examples will serve to illustrate the improved results obtained by polymerizing propylene oxide in the presence of the dicyclopentadiene adjuvant of this invention. The catalyst system used comprises triisobutylaluminum -and the vanadium salt of 2,4-pentanedione (vanadium acetylacetonate). It is obvious that the invention is not limited by the conditions and materials set forth in the examples. Thus, the vanadium-containing component in the catalyst can be any vanadium salt or vanadyl salt of a beta-diketone, or any vanadium or vanadyl halide. Similarly, the organoaluminum component in the catalyst can be any compound within the purview of the general formula herinbefore defined.

Examples l 6 1,2-epoxypropane, parts by weight 100 Dicyclopentadiene (DPCD), p.h.m. Variable Toluene or cyclohexane, parts by weight Variable Triisobutylaluminum (TBA), m.h.m. 30

Vanadium acetylacetonate [V(AA) rnhm. Variable Temperature, F. 158 Time, hours 48 Phrn.:parts by weight per 100 parts by weight epoxypropane.

B Ml1m.:gram millimoles per 100 grams epoxypropaue.

The polymerization technique used involved the steps of charging the diluent to the reactor and thereafter purging it with nitrogen. The 1,2-epoxypropane was then charged to the reactor followed by the organoaluminurn compound and the vanadium-containing compound. In the runs which illustrate the improvement obtained by the invention, the dicyclopentadiene was added immediately following the addition of the 1,2-epoxypropane. At the termination of each run, the viscosity of the reaction mixture was reduced by adding acetone, isopropyl alcohol, or a mixture of these materials. Approximately 1 Weight percent, based on the polymer, of 2,2-rnethylenebis(4-methyl-6-tertbutylphenol) antioxidant was added. The mixture was poured into water with high speed stirring and subsequently separated into an aqueous phase and an organic phase. The organic phase was removed I and the polymer was recovered from it by evaporating the diluent. The polymer product was then dried under vacuum. The polymers thus produced were observed to be gel-free. The results from the control runs and the several runs illustrating the improvements obtained by this invention are reported in Table I below. The crystallinity of each of the polymers was determined by dissolving 2 6 grams of the polymer in 200 ml. of acetone at 50 C. The TABLE II mixture was then cooled to about 30 C., filtered, and Crystalline the residue or undissolved portions of the polymer dried DCPD, Conv., Inh. polymer in an oven under vacuum. The solid or insoluble portion Example P- (P vise. (Wt. percent) represents the crystalline part of the polymer. 5 5 72 1.09 as In order to determine the inherent viscosity, one-tenth g8 ,2 gram of polymer was placed in a wire cage made from 30 71 1 88 52 80-mesh screen and the cage was placed in 100 ml. of toluene contained in a wide-mouth, 4-ounce bottle. After The data obtained by means of Examples 7 through standing at room temperature (approximately 77 F.) 10 show a relationship between the crystallinity and the quanfor about 24 hours, the cage was removed and the solutity of adjuvant employed. On the basis of this data it can tion filtered through a sulfur absorption tube of grade be seen that as the quantity of dicyclopentadiene is in- C porosity to remove any solid particles present. The recreased the crystallinity of the polymer increases. These sulting solution was run through a Medalia type viscomexamples further illustrate the operability of this inveneter supported in a 77 F. bath. The viscometer was tion'within all feasible ranges of adjuvant concentration. previously calibrated with toluene. The relative viscosity Although the highest degree of crystallinity is obtained is the ratio of the viscosity of the polymer solution to that when the polymerization is effected in the presence of a of toluene. The inherent viscosity is calculated by dividnon-aromatic diluent such as a parafiinic or a cycloparafing the natural logarithm of the relative viscosity by the finic hydrocarbon, it is obvious that aromatics can be used weight of the soluble portion of the original sample. as diluents if desired.

TABLE I Diluent Crystalline Increase in V(AA)3, DCPD, Comm, Inh. polymer crystallinity Example No. Type p.h.m (m.h.m.) (p.h.m.) Percent visc. (wt. percent) (percent) Control Toluene 860 2 0 67 3. 68 11 1 860 2 20 75 4. 36 22 100 860 4 0 62 4. 93 20 l. 860 4 20 72 5. 27 2s 860 e 0 50 4.40 23 860 6 20 65 a. 07 29 26 780 2 0 90 2.63 14 780 2 20 86 4.18 70 400 780 4 0 s7 2. 49 14 780 4 20 86 4.29 55 293 730 6 0 s0 3. 22 23 780 6 20 83 4.20 46 100 It is apparent from the data that a significant increase Although the invention has been described in considerin crystallinity is obtained when dicyclopentadiene is used able details, it must be understood that such detail is for during polymerization in accordance with this invention. 40 the purpose of illustration only and that many variations The crystallinity of the polymer increased from 26 to as and modifications can be made by one skilled in the art much as 400 percent with an average increase of about Without departing from the spirit and scope of the in- 127 prcent. Another improvement obtained by using the vention. adjuvant of this invention is that the green tensile strength I claim: of the polymers is increased. Green tensile strength rep- 1. In a process of polymerizing 1,2-epoxypropane in resents the tensile strength of the uncured polymer. The the presence of a catalyst system comprising an organogreen tensile strength from the polymers produced in the aluminium compound and a vanadium-containing comcontrol runs ranged from about 200 to about 400 p.s.i. pound wherein the mole ratio of said organoaluminum The polymer produced in Example No. 4 using dicyclocompound to said vanadium-containing compound is in pentadiene had a green tensile strength of about 1700 the range of from about 2:1 to 100:1, the improvement 3, comprising conducting said polymerization in the presence Examples 7-10 of dicyclopentadiene. 2. A process according to claim 1 wherein the dicyclo- A genes conducted wherebypropylen? .oxlde pentadiene is present in an amount of from about 1 to was polymenzed 1n the presence of varying quantities of about 50 Parts by weight per 100 parts by Weight dicyclopentadiene as the ad uvant. The catalyst system epoxy propane monomfir. comprised a mixture of triisobutylaluminum and vana- In a process of polymerizing 1,2 epoxypropane in drum acetylacetonate. The materials were charged to a the presence of a catalyst ystem comprising (a) an reactor the followmg Proportions: organoaluminum compound of the formula 1,2-epoxypropane, parts by weight 100 Dicyclopentadiene, p.h.m. Variable RnAlXm cyclohexane, Parts by weight 730 wherein R 1s a hydrocarbon radical selected from the Triisobutylaluminum .2 30 group cons1st1ng of saturated aliphatic, saturated cyclo- Vanadium acetylacetonate, In-h'mg 2 allphatic, and aromatlc containing from 1 to 20 carbon Temperature, 0 153 atoms, lncluslve; is a member of the class consisting Time, hours 43 of hydrogen,ffllgormeachlorgne, blromme, and iodine; n is p an integer 0 mm to inc usive; m is an integer lggggf by Welght per 100 pmts by weight epoxy from 0 to 2, inclusive; and the sum of the integers n and Mhm.=gram millimoles per 100 grams epoxypropane. m equals 3; and (b a vanadium containing compound The technique employed for polymerizing the propylene selected from the group consisting of vanadium halides, oxide was the same as that used in connection with Examvanadyl halides, vanadium salts of a beta-diketone; and ples 1 through 6. The crystallinity of each of the polymers vanadyl salts of a beta-diketone; wherein the mole ratio produced was determined in the same manner as the crysof said organoaluminum compound to said vanadiumtallinity was determined for the polymers produced by containing compound is in the range of from about 21 1 Examples 1 through 6. The results obtained by these exto 100:1; the improvement comprising conducting said amples are presented in Table II below. polymerization in the presence of dicyclopentadiene.

4. A process according to claim 3 wherein the dicyclopentadiene is present in an amount of from about 1 to about 50 parts by weight per 100 parts by Weight 1,2- epoxy propane monomer.

5. In a process of polymerizing 1,2-epoxypropane in the presence of a catalyst system comprising (a) an organoaluminum compound of the formula R AlX wherein R is a hydrocarbon radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 20 carbon atoms, inclusive; X is a member of the class consisting of hydrogen, fluorine, chlorine, bromine, and iodine; n; is an integer of from 1 to 3 inclusive; m is an integer of from to 2 inclusive; and the sum of the integers n and m equals 3; and (b) a vanadium-containing compound selected from the group consisting of vanadium halides, vanadyl halides, and vanadium salts of the formula wherein each R can be the same or different and is a radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 10 carbon atoms, inclusive; x is an integer of from 0 to 1; y is an integer from 1 to 4, inclusive; and the sum of the integers 2x and y equals the valence of the vanadium V; wherein the mole ratio of said organoaluminum compound to said vanadium-containing compound is in the range of from about 2:1 to 100:1; the improvement comprising conducting said polymerization in the presence of from about 1 to about 50 parts by weight dicyclopentadiene per 100 parts by weight 1,2- epoxypropane monomer,

6. A process according to claim 5 wherein said polymerization is carried out at a temperature within the range of about 40 to about 250 F.

7. A catalyst system comprising:

(a) an organoaluminum compound of the formula R AlX wherein R is a hydrocarbon radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 20 carbon atoms, inclusive; X is a member of the class consisting of hydrogen, fluorine, chlorine, -bromine, and iodine; n is an integer of from 1 to 3, inclusive; m is an integer from 0 to 2, inclusive; and the sum of the integers n and m equals 3;

(b) a vanadium-containing compound selected from the group consisting of vanadium halides, vanadyl halides, and vanadium salts of the formula wherein each R can be the same or different and is a radical selected from the group consisting of saturated aliphatic, saturated cycloaliphatic, and aromatic containing from 1 to 10 carbon atoms, inclusive; x is an integer of from 0 to 1; y is an integer of from 1 to 4, inclusive; and the sum of the integers 2x and y equals the valence of the vanadium V; the mole ratio of said organoaluminum compound to said vanadium-containing compound being in the range of about 2:1 to about 100:1; and

(c) dicyclopentadiene.

8. A catalyst system according to claim 7 wherein, the dicyclopentadiene is present in an amount within the range of about 1 to about parts by weight per parts by weight 1,2-epoxy propane monomer.

References Cited J. of Polymer Science, vol. 51, issue 156 (1961), (pp. 57-810 relied on).

HARRY WONG, JR., Primary Examiner US. Cl. X.R. 252429, 431, 32.8 

